Yield stability and carbon sequestration of agricultural systems are impacted by nutrient management strategies. Major objectives of this study were to understand the effects of long-term (43 years) manure application on a) environmental parameters such as soil organic carbon (SOC) sequestration, enzyme activities in surface and subsurface layers, and b) yield, and yield stability under a soybean–wheat cropping system in a Vertisol. For this, 100% recommended dose of nitrogen (N), N and phosphorus (NP), N, P and potassium (NPK), NPK + farmyard manure (NPKM) was compared with an unfertilized control (UC) and a fallow land. After 43 years, NPKM and NPK plots had ∼63 and 30% higher total SOC stock than UC, and 45 and 17% higher total SOC stock than fallow plots, respectively in the 0–30 cm layer. Acid hydrolysable C was ~ 42 and 57% higher for NPKM plots in those layers respectively than fallow land. The proportion of macroaggregates was less than 30% in both soil layers of cultivated plots. NPKM had 44 and 28% greater humic and fulvic acid-associated C than fallow land in top layer. Enzyme activities improved in NPKM by ~ 60 and 61% as compared with fallow land. A steady decline in soybean productivity over the years might be due to residue effect. However, wheat yield increased steadily with manuring. Higher SOC accumulation (p < .001), greater enzyme activities (p < .05), improved structure (p < .05) could enhance wheat yield under NPKM. Thus, manure application could lead to yield stability and enhance SOC sequestration in subtropical region simultaneously.

中文翻译：

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长期施用肥料以改善亚热带地区的作物产量和固碳

养分管理策略会影响农业系统的产量稳定性和碳固存。这项研究的主要目的是了解长期施肥（43年）对a）环境参数（如土壤有机碳（SOC）隔离，表层和地下层的酶活性以及b）产量和产量）的影响。在Vertisol的大豆-小麦种植系统下具有较高的稳定性。为此，将100％推荐剂量的氮（N），氮和磷（NP），氮，磷和钾（NPK），NPK +农家肥（NPKM）与未施肥的对照（UC）和休耕地进行了比较。43年后，在0-30 cm的层中，NPKM和NPK地块的总SOC量比UC高出约63％和30％，SOC总数比休耕地的SOC高出45％和17％。在这些层中，NPKM样地的酸可水解碳分别比休耕地高约42％和57％。在耕地的两个土壤层中，大型骨料的比例均小于30％。与顶层休耕地相比，NPKM的腐殖酸和黄腐酸相关的碳含量分别高44％和28％。与休耕地相比，NPKM中的酶活性提高了约60％和61％。多年来大豆生产力的稳定下降可能是由于残留效应所致。但是，随着施肥，小麦单产稳步增长。更高的SOC累积量（与休耕地相比，NPKM中的酶活性提高了约60％和61％。多年来大豆生产力的稳定下降可能是由于残留效应所致。但是，随着施肥，小麦单产稳步增长。更高的SOC累积量（与休耕地相比，NPKM中的酶活性提高了约60％和61％。多年来大豆生产力的稳定下降可能是由于残留效应所致。但是，随着施肥，小麦单产稳步增长。更高的SOC累积量（p  <.001），更大的酶活性（p  <.05），改善的结构（p  <.05）可以提高NPKM条件下的小麦产量。因此，施用肥料可以导致产量稳定并同时增强亚热带地区的SOC隔离。